1. Field of the Invention
The present invention relates to an image forming apparatus which can accept a plurality of job data, which carries out copying and printing based on the accepted job and which can carry out a post-processing for the recording medium which has been copied or printed, an image forming method and a computer readable recording medium storing a program.
2. Description of Related Art
In recent years, an image forming apparatus which executes the print jobs (an image data and an output condition of the image data) instructing the image forming operations transmitted from personal computers or the like which are network connected in the order of acceptance, which carries out an image forming process for the recording medium, and which comprises a finisher (post-processing function) to automatically carry out a part of the operation such as a stapling, a punching, a sheet-cutting process, a cutting process and the like for a bundle of recording medium after the image forming process which used to be carried out by man power is being developed.
When a plurality of print jobs are received, the above described image forming apparatus executes the print jobs in the order of acceptance. Therefore, in a case where there are many print jobs which take time for post-processing, there is no choice but to temporarily stop the image forming unit which carries out the image forming, and a great amount of time is needed until all of the images of the received print jobs are formed on the recording medium based on each print job. Thus, there is a problem that the productivity declines.
For example, JP2003-54805A discloses a technique for shortening the post-processing time by the image forming apparatus comprising a driving unit in each carrying passage of an entrance carrying passage of a recording paper to be ejected, a carrying passage in a direction of the paper ejection tray of the body from the first switching unit and a carrying passage in a direction of the elevating paper ejection tray or the fixed paper ejection tray, by detecting the position of the recording paper which is in the middle of the carrying passage, and by independently determining the carrying rate and the timing as a method to solve the problem of the reduction of productivity.
Moreover, JP2004-323192A discloses a post-processing apparatus including a sorting unit which disposes the paper to with the binding process at the binding process position or which disposes the paper without the binding process at the paper ejection position according to the way of post-processing of the paper, a binding process unit to carry out the binding process for the paper disposed at the binding process position and a paper ejection unit to eject the paper disposed at the paper ejection position outside.
Furthermore, JP2006-1044A discloses a technique of changing the execution order of the jobs according to each of the content of the post-processing of the executed job and the registered job (either one of the type of the post-processing, the carrying passage used when the post-processing is carried out, the output of the recording medium to be output and the length of the time needed for the post-processing).
However, the timing to execute the next job is not suggested in the conventional technique such as the technique disclosed in JP2003-54805A or JP2004-323192A. Therefore, the timing in which the next job to be executed is not clear. Further, in the conventional technique such as the technique disclosed in JP2006-1044A, there is a possibility that a case where the image forming process of the foregoing job which is to be restarted after the interrupted job is made to be on stand-by occurs according to the time needed for the image forming of the next job which was allowed to interrupt during the foregoing job which is divided in each copy when the image forming process of the next job is executed during the post-processing of the job which is being executed earlier. Therefore, the ending time of all copies of the foregoing job will be delayed, and there remains a problem that the entire productivity declines.